Tea tests live in ordinary Tea files. Define `test` blocks, import assertion helpers from `std.assert`, and run everything through `tea test`.
## Write a test block
A test block gives a named test case a small body of executable Tea code. Inside it, use assertion helpers to check expectations and fail fast when behavior changes.
```tea
use assert from "std.assert"
test "list length stays stable"
var words = ["tea", "lang"]
assert.ok(@len(words) == 2)
assert.eq(words[0], "tea")
assert.ne(words[1], "chai")
end
```
## Assertion helpers
The standard assertion module covers the common cases: truthy checks, equality checks, inequality checks, and snapshot helpers when you want to compare output against stored expectations.
```tea
use assert from "std.assert"
test "basic assertions"
assert.ok(1 + 1 == 2)
assert.eq("tea", "tea")
assert.ne("tea", "chai")
end
```
## Run tests
Run the whole test suite or target a narrower path. The CLI can also list discovered tests or filter down to a subset when you only want to rerun one area.
```bash
tea test
tea test tests/
tea test --list
tea test --filter strings
tea test --update-snapshots
```
- `std.assert` exports `ok`, `eq`, `ne`, and `snapshot`.
- The CLI discovers Tea `test` blocks from paths you pass in.
-
Snapshot support exists in the stdlib and CLI surface, but backend support
is still uneven.